Home |
Search |
Today's Posts |
#1
![]() |
|||
|
|||
![]()
I am trying to help a friend replace the steel cable that raises the
swing keel on his old San Juan 21. Do any of you have a drawing or can you describe how the cable runs. I thought that it would run straight from a winch at the aft end of the centerboard trunk in the cabin down to the aft/lower end of the swing keel. But, from what we can see so far the cable runs forward from the winch. This would only make sense if the cable runs to a block forward of the keel and then is attached to the aft/upper end of the keel. Since the keel is about 500 pounds, that would seem to be an unnecessarily straining design. We have also looked at another SJ 21. Amazingly, its keel winch is at the forward end of the centerboard trunk. Thanks for any help you can give us. Lee Huddleston s/v Truelove |
#2
![]() |
|||
|
|||
![]()
not familiar with the boat but how are you going to go about replacing the
cable? if you intend to haul the boat and lower the swing keel to get at it from below then you should be able to shine a light up into the slot and see what's up there. Lee Huddleston ) writes: I am trying to help a friend replace the steel cable that raises the swing keel on his old San Juan 21. Do any of you have a drawing or can you describe how the cable runs. I thought that it would run straight from a winch at the aft end of the centerboard trunk in the cabin down to the aft/lower end of the swing keel. But, from what we can see so far the cable runs forward from the winch. This would only make sense if the cable runs to a block forward of the keel and then is attached to the aft/upper end of the keel. Since the keel is about 500 pounds, that would seem to be an unnecessarily straining design. We have also looked at another SJ 21. Amazingly, its keel winch is at the forward end of the centerboard trunk. Thanks for any help you can give us. Lee Huddleston s/v Truelove -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-freenet email must have "notspam" in subject or it's returned |
#3
![]() |
|||
|
|||
![]()
Lee Huddleston wrote:
I am trying to help a friend replace the steel cable that raises the swing keel on his old San Juan 21. Do any of you have a drawing or can you describe how the cable runs. They used at least three different configurations on these boats. The best thing to do is going to be to remove the pivot bolt, lower the keel out of the trunk, and replace the cable and the pivot and check inside the trunk for damage. If you go here http://bbs.trailersailor.com/forums/...ilor/index.cgi you'll be able to talk with at least one person who has done this job on a San Juan 21. Fresh Breezes- Doug King |
#4
![]() |
|||
|
|||
![]()
Thanks for the advice.
You are both right that we will have to figure out a way to drop the keel at least some to get to the cable connection. I was just trying to figure out how far it might have to be dropped. If the attachment is on the aft/lower end of the keel, we might not have to do much more than lift the stern a little. If the attachment is at the aft/upper end, we may have to take the suggestion of completely removing the keel by disconnecting the pivot. I would really like to avoid that since the keel is so heavy, but may have to is there is no other way to get up inside the well. One of the constraints for us is the lack of any hoist in our area. What would you think of this "crazy" idea? Since the SJ 21 is a relatively light boat with most of the weight in the keel, carefully slide the boat off the back of the trailer onto grass. Then roll the boat over on its side and pull the keel out to work on it (without disconnecting at the pivot). The boat on the trailer is only about a foot off of the ground. It might not take too much to raise it just a little to get it off and then back on the trailer. Lee Huddleston |
#5
![]() |
|||
|
|||
![]() One of the constraints for us is the lack of any hoist in our area. What would you think of this "crazy" idea? Since the SJ 21 is a relatively light boat with most of the weight in the keel, carefully slide the boat off the back of the trailer onto grass. Then roll the boat over on its side and pull the keel out to work on it (without disconnecting at the pivot). The boat on the trailer is only about a foot off of the ground. It might not take too much to raise it just a little to get it off and then back on the trailer. only problem I can see is lowering the keel once the boat is on its side. you might have to lower the keel as you roll the boat. I don't know for sure how that particular boat would take the strain of lying on its side on the ground but I doubt it would be a problem. You might have to spread the strain. Someobdy else should know. -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-freenet email must have "notspam" in subject or it's returned |
#6
![]() |
|||
|
|||
![]()
Lee Huddleston wrote:
... If the attachment is at the aft/upper end, we may have to take the suggestion of completely removing the keel by disconnecting the pivot. I would really like to avoid that since the keel is so heavy, but may have to is there is no other way to get up inside the well. Another option is to saw off the top of the trunk and get at it that way. You can either build a new fiberglas top molded in place, or build up a flange and put on a removable panel. One of the constraints for us is the lack of any hoist in our area. What would you think of this "crazy" idea? Since the SJ 21 is a relatively light boat with most of the weight in the keel, carefully slide the boat off the back of the trailer onto grass. Then roll the boat over on its side and pull the keel out to work on it (without disconnecting at the pivot). I think that 1- the boat won't like sitting on it's side on a hard surface and 2- pulling the keel out sideways is going to be a much bigger PITA than lowering it. ... The boat on the trailer is only about a foot off of the ground. It might not take too much to raise it just a little to get it off and then back on the trailer. Borrow a mechanics pit, or jack the boat up on it's trailer and prop it up solidly to work under. You don't have to raise the boat all at once, if you do it a little at a time it's easy & secure. All you need is a scissors jack (or better) and a supply of cinder blocks. Or drive it between two trees and use a chainfall to hoist it up. There's more than one way to skin a cat! |
#7
![]() |
|||
|
|||
![]()
Thanks very much to everyone who responded. I got the problem solved
with much less hassle than I anticipated. I had based by thoughts on how to get to the connection of the cable to the keel on the descriptions of the owner of the boat. Turns out that was a mistake. I did not have to cut off the top of the centerboard trunk as was suggested. There was a piece that simply unscrewed and gave complete access to the top of the keel and the entire system. I found that the cable does, surprisingly, attach to the upper/aft end of the keel. It goes like this: The end of the cable goes through a hole in the mast compression post and is pinned with a bolt. The cable runs aft to a block attached to the keel. It makes a 180 degree turn and then run forward to a sheeve (sp?) also in the forward side of the mast compression post. The cable makes another 180 degree turn around the sheeve and heads aft through a hole in the top of the centerboard trunk to a winch on the aft end of the trunk. Did that make sense? The point is, the entire apparatus is accessible from the cabin (with the keel up). Local folks have recommended using a galvanized steel cable designed for a trailer winch rather than trying to use stainless steel. Besides the significant difference in cost, the galvanized steel will wind on the winch easier without breaking. Since we are sailing in fresh water, the galvanized probably will last for many years without rusting. What do you all think? Lee Huddleston |
#8
![]() |
|||
|
|||
![]()
Lee Huddleston wrote:
Thanks very much to everyone who responded. I got the problem solved with much less hassle than I anticipated. Was your boat built in New Bern? A lot of the SJ21s built there have the access panel, I think the west coast boats kept the trunk solid for a few years after. Local folks have recommended using a galvanized steel cable designed for a trailer winch rather than trying to use stainless steel. Galzanized is more flexible and will hold up better. The only issue is that the galzanizing will break down after a few years and then the rust cycle starts again... but you've gained some time. Menawhile, now you know how to replace it! Fresh Breezes- Doug King |
#9
![]() |
|||
|
|||
![]()
Lee Huddleston ) writes:
I found that the cable does, surprisingly, attach to the upper/aft end of the keel. It goes like this: The end of the cable goes through a hole in the mast compression post and is pinned with a bolt. The cable runs aft to a block attached to the keel. It makes a 180 degree turn and then run forward to a sheeve (sp?) also in the forward side of the mast compression post. The cable makes another 180 degree turn around the sheeve and heads aft through a hole in the top of the centerboard trunk to a winch on the aft end of the trunk. Did that make sense? running the cable thorough blocks like that provides mechanical advantage which reduces the force needed to raise the 500 lb. I think from your description the force is 1/3 of what you'd need to raise the weight directly. -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-freenet email must have "notspam" in subject or it's returned |
#10
![]() |
|||
|
|||
![]()
Doug King,
The boat belongs to a friend, but I suspect that you are correct. There was an access panel on top of the centerboard trunk that made working on the cable a snap. My late brother had a SJ21 which does not have the access panel. Lee Huddleston |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
From swing keel to fixed keel | Boat Building | |||
This war is On-Topic, really, Part One, very long | General | |||
back with a problem now | General | |||
C&C Corvette Floor and Keel Questions | Boat Building |